抑制变压器直流偏磁的串接电阻措施

高压直流输电系统单极大地回线方式运行时,巨大的入地电流将会使接地板附近的变电站主变压器产生直流偏磁,对交流系统造成不利影响.文中论证了在变压器中性点串接电阻器限制地中直流流入的可行性,并从抑制中性点直流与过电压效果和继电保护角度分析及校核了中性点电阻器对系统造成的影响.研究表明,这是一种简单有效的抑制变压器中性点直流电流的措施.

Applying Series Resistor to Restrain Power Transformer DC Biasing

The enormous ground return current caused by HVDC (high voltage direct current) system's mono-pole ground return operation mode will result in the main transformer DC biasing at the substations near the ground electrode, thus it has disadvantageous effect on AC (alternative current) system. This paper introduces the measure by using a series neutral resistor to restrain the DC ground current into the transformer. Also, the effects of the application on restraining the neutral current, AC system over-voltage and relay protection are analyzed and checked out. The measure is then proved effective to restrain power transformer DC biasing with analysis result.